Generally, RFID systems interchange various data with each other using radio waves at a predetermined bandwidth.
An RFID system includes a tag (or transponder) and a reader (or interrogator). The tag includes unique identification information. The tag is attached to an object or an animal, for example. The reader reads/writes identification information from/to the tag.
The reader can recognize, track, and manage the tag attached to, for example, a product, an animal, or a person by a contact or non-contact manner. Further, the reader can record information to the tag.
FIG. 1 illustrates an RFID tag 10 according to the related art.
Referring to FIG. 1, the RFID tag 10 includes a semiconductor chip 20 and an antenna 30. The semiconductor chip 20 transmits or receives radio wave frequencies through the antenna 30.
The RFID tag 10 reflects a signal of a predetermined radio frequency (RF) band which is transmitted from an RFID reader (not shown). Here, the RFID tag 10 modulates the RF signal to add identification information and transmits to the RFID reader.
The antenna 30 of the RFID tag 10 is formed on an insulation film 40 in the form of a dipole antenna by printing. Therefore, a null exists in a certain direction of the dipole-type antenna 30 where a radiation pattern is not formed, and thus the RFID tag 10 cannot normally communicate with an RFID reader in the null direction.